1. Field of the Invention
This invention is directed to coating compositions, in particular, to durable and weatherable coating compositions useful as clear finishes for automobiles and trucks.
2. Description of the Prior Art
The finishing system of choice presently being used on the exterior of automobiles and trucks comprises a clear coating applied over pigmented base coating that is applied over a primer coating. The clear coating provides protection, in particular protection from weathering, to the pigmented base coating and improves the appearance of the overall finish, in particular, provides improved gloss and distinctness of image. When used in refinishing of automobile and truck bodies, the clear coating is required to have a reasonably short cure time period to allow for further processing or handling of the vehicle with out damaging the finish.
The following US Patents: U.S. Pat. No. 5,516,873, U.S. Pat. No. 5,126,170, U.S. Pat. No. 5,243,012, U.S. Pat. No. 5,236,741, U.S. Pat. No. 5,412,056, U.S. Pat. No. 5,580,945, and U.S. Pat. No. 6,005,062, show a variety of coating composition that contain polyaspartic acid derivatives but coating compositions formulated according to the teaching of these patents do not have the combination of properties of rapid cure and excellent weatherability that are currently desired for clear coating compositions and in particular, for such compositions that are used for the repair of the finishes of automotive and truck exterior finishes.
It would be desirable to form a clear coating composition that cures rapidly after application and provides a protective clear finish that has good gloss and distinctness of image that provides an excellent appearance, has excellent weatherability, in particular resistance to U.V. (ultraviolet light) degradation and also hardens in a reasonably short time after application.